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1da177e4 LT |
1 | /* Linux driver for NAND Flash Translation Layer */ |
2 | /* (c) 1999 Machine Vision Holdings, Inc. */ | |
3 | /* Author: David Woodhouse <dwmw2@infradead.org> */ | |
97894cda | 4 | /* $Id: nftlcore.c,v 1.98 2005/11/07 11:14:21 gleixner Exp $ */ |
1da177e4 LT |
5 | |
6 | /* | |
7 | The contents of this file are distributed under the GNU General | |
8 | Public License version 2. The author places no additional | |
9 | restrictions of any kind on it. | |
10 | */ | |
11 | ||
12 | #define PRERELEASE | |
13 | ||
1da177e4 LT |
14 | #include <linux/kernel.h> |
15 | #include <linux/module.h> | |
16 | #include <asm/errno.h> | |
17 | #include <asm/io.h> | |
18 | #include <asm/uaccess.h> | |
19 | #include <linux/miscdevice.h> | |
20 | #include <linux/pci.h> | |
21 | #include <linux/delay.h> | |
22 | #include <linux/slab.h> | |
23 | #include <linux/sched.h> | |
24 | #include <linux/init.h> | |
25 | #include <linux/hdreg.h> | |
26 | ||
27 | #include <linux/kmod.h> | |
28 | #include <linux/mtd/mtd.h> | |
29 | #include <linux/mtd/nand.h> | |
30 | #include <linux/mtd/nftl.h> | |
31 | #include <linux/mtd/blktrans.h> | |
32 | ||
33 | /* maximum number of loops while examining next block, to have a | |
34 | chance to detect consistency problems (they should never happen | |
35 | because of the checks done in the mounting */ | |
36 | ||
37 | #define MAX_LOOPS 10000 | |
38 | ||
39 | ||
40 | static void nftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd) | |
41 | { | |
42 | struct NFTLrecord *nftl; | |
43 | unsigned long temp; | |
44 | ||
45 | if (mtd->type != MTD_NANDFLASH) | |
46 | return; | |
47 | /* OK, this is moderately ugly. But probably safe. Alternatives? */ | |
48 | if (memcmp(mtd->name, "DiskOnChip", 10)) | |
49 | return; | |
50 | ||
51 | if (!mtd->block_isbad) { | |
52 | printk(KERN_ERR | |
53 | "NFTL no longer supports the old DiskOnChip drivers loaded via docprobe.\n" | |
54 | "Please use the new diskonchip driver under the NAND subsystem.\n"); | |
55 | return; | |
56 | } | |
57 | ||
58 | DEBUG(MTD_DEBUG_LEVEL1, "NFTL: add_mtd for %s\n", mtd->name); | |
59 | ||
60 | nftl = kmalloc(sizeof(struct NFTLrecord), GFP_KERNEL); | |
61 | ||
62 | if (!nftl) { | |
63 | printk(KERN_WARNING "NFTL: out of memory for data structures\n"); | |
64 | return; | |
65 | } | |
66 | memset(nftl, 0, sizeof(*nftl)); | |
67 | ||
68 | nftl->mbd.mtd = mtd; | |
69 | nftl->mbd.devnum = -1; | |
19187672 | 70 | |
1da177e4 | 71 | nftl->mbd.tr = tr; |
1da177e4 LT |
72 | |
73 | if (NFTL_mount(nftl) < 0) { | |
74 | printk(KERN_WARNING "NFTL: could not mount device\n"); | |
75 | kfree(nftl); | |
76 | return; | |
77 | } | |
78 | ||
79 | /* OK, it's a new one. Set up all the data structures. */ | |
80 | ||
81 | /* Calculate geometry */ | |
82 | nftl->cylinders = 1024; | |
83 | nftl->heads = 16; | |
84 | ||
85 | temp = nftl->cylinders * nftl->heads; | |
86 | nftl->sectors = nftl->mbd.size / temp; | |
87 | if (nftl->mbd.size % temp) { | |
88 | nftl->sectors++; | |
89 | temp = nftl->cylinders * nftl->sectors; | |
90 | nftl->heads = nftl->mbd.size / temp; | |
91 | ||
92 | if (nftl->mbd.size % temp) { | |
93 | nftl->heads++; | |
94 | temp = nftl->heads * nftl->sectors; | |
95 | nftl->cylinders = nftl->mbd.size / temp; | |
96 | } | |
97 | } | |
98 | ||
99 | if (nftl->mbd.size != nftl->heads * nftl->cylinders * nftl->sectors) { | |
100 | /* | |
97894cda | 101 | Oh no we don't have |
1da177e4 LT |
102 | mbd.size == heads * cylinders * sectors |
103 | */ | |
104 | printk(KERN_WARNING "NFTL: cannot calculate a geometry to " | |
105 | "match size of 0x%lx.\n", nftl->mbd.size); | |
106 | printk(KERN_WARNING "NFTL: using C:%d H:%d S:%d " | |
107 | "(== 0x%lx sects)\n", | |
97894cda | 108 | nftl->cylinders, nftl->heads , nftl->sectors, |
1da177e4 LT |
109 | (long)nftl->cylinders * (long)nftl->heads * |
110 | (long)nftl->sectors ); | |
111 | } | |
112 | ||
113 | if (add_mtd_blktrans_dev(&nftl->mbd)) { | |
fa671646 JJ |
114 | kfree(nftl->ReplUnitTable); |
115 | kfree(nftl->EUNtable); | |
1da177e4 LT |
116 | kfree(nftl); |
117 | return; | |
118 | } | |
119 | #ifdef PSYCHO_DEBUG | |
120 | printk(KERN_INFO "NFTL: Found new nftl%c\n", nftl->mbd.devnum + 'a'); | |
121 | #endif | |
122 | } | |
123 | ||
124 | static void nftl_remove_dev(struct mtd_blktrans_dev *dev) | |
125 | { | |
126 | struct NFTLrecord *nftl = (void *)dev; | |
127 | ||
128 | DEBUG(MTD_DEBUG_LEVEL1, "NFTL: remove_dev (i=%d)\n", dev->devnum); | |
129 | ||
130 | del_mtd_blktrans_dev(dev); | |
fa671646 JJ |
131 | kfree(nftl->ReplUnitTable); |
132 | kfree(nftl->EUNtable); | |
1da177e4 LT |
133 | kfree(nftl); |
134 | } | |
135 | ||
8593fbc6 TG |
136 | /* |
137 | * Read oob data from flash | |
138 | */ | |
139 | int nftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len, | |
140 | size_t *retlen, uint8_t *buf) | |
141 | { | |
142 | struct mtd_oob_ops ops; | |
143 | int res; | |
144 | ||
145 | ops.mode = MTD_OOB_PLACE; | |
146 | ops.ooboffs = offs & (mtd->writesize - 1); | |
147 | ops.ooblen = len; | |
148 | ops.oobbuf = buf; | |
149 | ops.datbuf = NULL; | |
8593fbc6 TG |
150 | |
151 | res = mtd->read_oob(mtd, offs & ~(mtd->writesize - 1), &ops); | |
7014568b | 152 | *retlen = ops.oobretlen; |
8593fbc6 TG |
153 | return res; |
154 | } | |
155 | ||
156 | /* | |
157 | * Write oob data to flash | |
158 | */ | |
159 | int nftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len, | |
160 | size_t *retlen, uint8_t *buf) | |
161 | { | |
162 | struct mtd_oob_ops ops; | |
163 | int res; | |
164 | ||
165 | ops.mode = MTD_OOB_PLACE; | |
166 | ops.ooboffs = offs & (mtd->writesize - 1); | |
167 | ops.ooblen = len; | |
168 | ops.oobbuf = buf; | |
169 | ops.datbuf = NULL; | |
8593fbc6 TG |
170 | |
171 | res = mtd->write_oob(mtd, offs & ~(mtd->writesize - 1), &ops); | |
7014568b | 172 | *retlen = ops.oobretlen; |
8593fbc6 TG |
173 | return res; |
174 | } | |
175 | ||
553a8012 FD |
176 | #ifdef CONFIG_NFTL_RW |
177 | ||
8593fbc6 TG |
178 | /* |
179 | * Write data and oob to flash | |
180 | */ | |
181 | static int nftl_write(struct mtd_info *mtd, loff_t offs, size_t len, | |
182 | size_t *retlen, uint8_t *buf, uint8_t *oob) | |
183 | { | |
184 | struct mtd_oob_ops ops; | |
185 | int res; | |
186 | ||
187 | ops.mode = MTD_OOB_PLACE; | |
188 | ops.ooboffs = offs; | |
189 | ops.ooblen = mtd->oobsize; | |
190 | ops.oobbuf = oob; | |
191 | ops.datbuf = buf; | |
192 | ops.len = len; | |
193 | ||
194 | res = mtd->write_oob(mtd, offs & ~(mtd->writesize - 1), &ops); | |
195 | *retlen = ops.retlen; | |
196 | return res; | |
197 | } | |
198 | ||
1da177e4 LT |
199 | /* Actual NFTL access routines */ |
200 | /* NFTL_findfreeblock: Find a free Erase Unit on the NFTL partition. This function is used | |
201 | * when the give Virtual Unit Chain | |
202 | */ | |
203 | static u16 NFTL_findfreeblock(struct NFTLrecord *nftl, int desperate ) | |
204 | { | |
205 | /* For a given Virtual Unit Chain: find or create a free block and | |
206 | add it to the chain */ | |
207 | /* We're passed the number of the last EUN in the chain, to save us from | |
208 | having to look it up again */ | |
209 | u16 pot = nftl->LastFreeEUN; | |
210 | int silly = nftl->nb_blocks; | |
211 | ||
212 | /* Normally, we force a fold to happen before we run out of free blocks completely */ | |
213 | if (!desperate && nftl->numfreeEUNs < 2) { | |
214 | DEBUG(MTD_DEBUG_LEVEL1, "NFTL_findfreeblock: there are too few free EUNs\n"); | |
215 | return 0xffff; | |
216 | } | |
217 | ||
218 | /* Scan for a free block */ | |
219 | do { | |
220 | if (nftl->ReplUnitTable[pot] == BLOCK_FREE) { | |
221 | nftl->LastFreeEUN = pot; | |
222 | nftl->numfreeEUNs--; | |
223 | return pot; | |
224 | } | |
225 | ||
226 | /* This will probably point to the MediaHdr unit itself, | |
227 | right at the beginning of the partition. But that unit | |
228 | (and the backup unit too) should have the UCI set | |
229 | up so that it's not selected for overwriting */ | |
230 | if (++pot > nftl->lastEUN) | |
231 | pot = le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN); | |
232 | ||
233 | if (!silly--) { | |
234 | printk("Argh! No free blocks found! LastFreeEUN = %d, " | |
97894cda | 235 | "FirstEUN = %d\n", nftl->LastFreeEUN, |
1da177e4 LT |
236 | le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN)); |
237 | return 0xffff; | |
238 | } | |
239 | } while (pot != nftl->LastFreeEUN); | |
240 | ||
241 | return 0xffff; | |
242 | } | |
243 | ||
244 | static u16 NFTL_foldchain (struct NFTLrecord *nftl, unsigned thisVUC, unsigned pendingblock ) | |
245 | { | |
f4a43cfc | 246 | struct mtd_info *mtd = nftl->mbd.mtd; |
1da177e4 LT |
247 | u16 BlockMap[MAX_SECTORS_PER_UNIT]; |
248 | unsigned char BlockLastState[MAX_SECTORS_PER_UNIT]; | |
249 | unsigned char BlockFreeFound[MAX_SECTORS_PER_UNIT]; | |
250 | unsigned int thisEUN; | |
251 | int block; | |
252 | int silly; | |
253 | unsigned int targetEUN; | |
254 | struct nftl_oob oob; | |
255 | int inplace = 1; | |
f4a43cfc | 256 | size_t retlen; |
1da177e4 LT |
257 | |
258 | memset(BlockMap, 0xff, sizeof(BlockMap)); | |
259 | memset(BlockFreeFound, 0, sizeof(BlockFreeFound)); | |
260 | ||
261 | thisEUN = nftl->EUNtable[thisVUC]; | |
262 | ||
263 | if (thisEUN == BLOCK_NIL) { | |
264 | printk(KERN_WARNING "Trying to fold non-existent " | |
265 | "Virtual Unit Chain %d!\n", thisVUC); | |
266 | return BLOCK_NIL; | |
267 | } | |
97894cda | 268 | |
1da177e4 LT |
269 | /* Scan to find the Erase Unit which holds the actual data for each |
270 | 512-byte block within the Chain. | |
271 | */ | |
f4a43cfc | 272 | silly = MAX_LOOPS; |
1da177e4 LT |
273 | targetEUN = BLOCK_NIL; |
274 | while (thisEUN <= nftl->lastEUN ) { | |
f4a43cfc | 275 | unsigned int status, foldmark; |
1da177e4 LT |
276 | |
277 | targetEUN = thisEUN; | |
278 | for (block = 0; block < nftl->EraseSize / 512; block ++) { | |
8593fbc6 | 279 | nftl_read_oob(mtd, (thisEUN * nftl->EraseSize) + |
f4a43cfc TG |
280 | (block * 512), 16 , &retlen, |
281 | (char *)&oob); | |
1da177e4 | 282 | if (block == 2) { |
f4a43cfc TG |
283 | foldmark = oob.u.c.FoldMark | oob.u.c.FoldMark1; |
284 | if (foldmark == FOLD_MARK_IN_PROGRESS) { | |
285 | DEBUG(MTD_DEBUG_LEVEL1, | |
286 | "Write Inhibited on EUN %d\n", thisEUN); | |
1da177e4 LT |
287 | inplace = 0; |
288 | } else { | |
289 | /* There's no other reason not to do inplace, | |
290 | except ones that come later. So we don't need | |
291 | to preserve inplace */ | |
292 | inplace = 1; | |
293 | } | |
294 | } | |
f4a43cfc | 295 | status = oob.b.Status | oob.b.Status1; |
1da177e4 LT |
296 | BlockLastState[block] = status; |
297 | ||
298 | switch(status) { | |
299 | case SECTOR_FREE: | |
300 | BlockFreeFound[block] = 1; | |
301 | break; | |
302 | ||
303 | case SECTOR_USED: | |
304 | if (!BlockFreeFound[block]) | |
305 | BlockMap[block] = thisEUN; | |
306 | else | |
97894cda | 307 | printk(KERN_WARNING |
1da177e4 LT |
308 | "SECTOR_USED found after SECTOR_FREE " |
309 | "in Virtual Unit Chain %d for block %d\n", | |
310 | thisVUC, block); | |
311 | break; | |
312 | case SECTOR_DELETED: | |
313 | if (!BlockFreeFound[block]) | |
314 | BlockMap[block] = BLOCK_NIL; | |
315 | else | |
97894cda | 316 | printk(KERN_WARNING |
1da177e4 LT |
317 | "SECTOR_DELETED found after SECTOR_FREE " |
318 | "in Virtual Unit Chain %d for block %d\n", | |
319 | thisVUC, block); | |
320 | break; | |
321 | ||
322 | case SECTOR_IGNORE: | |
323 | break; | |
324 | default: | |
325 | printk("Unknown status for block %d in EUN %d: %x\n", | |
326 | block, thisEUN, status); | |
327 | } | |
328 | } | |
329 | ||
330 | if (!silly--) { | |
331 | printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%x\n", | |
332 | thisVUC); | |
333 | return BLOCK_NIL; | |
334 | } | |
97894cda | 335 | |
1da177e4 LT |
336 | thisEUN = nftl->ReplUnitTable[thisEUN]; |
337 | } | |
338 | ||
339 | if (inplace) { | |
340 | /* We're being asked to be a fold-in-place. Check | |
341 | that all blocks which actually have data associated | |
97894cda | 342 | with them (i.e. BlockMap[block] != BLOCK_NIL) are |
1da177e4 LT |
343 | either already present or SECTOR_FREE in the target |
344 | block. If not, we're going to have to fold out-of-place | |
345 | anyway. | |
346 | */ | |
347 | for (block = 0; block < nftl->EraseSize / 512 ; block++) { | |
348 | if (BlockLastState[block] != SECTOR_FREE && | |
349 | BlockMap[block] != BLOCK_NIL && | |
350 | BlockMap[block] != targetEUN) { | |
351 | DEBUG(MTD_DEBUG_LEVEL1, "Setting inplace to 0. VUC %d, " | |
352 | "block %d was %x lastEUN, " | |
353 | "and is in EUN %d (%s) %d\n", | |
354 | thisVUC, block, BlockLastState[block], | |
97894cda | 355 | BlockMap[block], |
1da177e4 LT |
356 | BlockMap[block]== targetEUN ? "==" : "!=", |
357 | targetEUN); | |
358 | inplace = 0; | |
359 | break; | |
360 | } | |
361 | } | |
362 | ||
363 | if (pendingblock >= (thisVUC * (nftl->EraseSize / 512)) && | |
364 | pendingblock < ((thisVUC + 1)* (nftl->EraseSize / 512)) && | |
365 | BlockLastState[pendingblock - (thisVUC * (nftl->EraseSize / 512))] != | |
366 | SECTOR_FREE) { | |
367 | DEBUG(MTD_DEBUG_LEVEL1, "Pending write not free in EUN %d. " | |
368 | "Folding out of place.\n", targetEUN); | |
369 | inplace = 0; | |
370 | } | |
371 | } | |
97894cda | 372 | |
1da177e4 LT |
373 | if (!inplace) { |
374 | DEBUG(MTD_DEBUG_LEVEL1, "Cannot fold Virtual Unit Chain %d in place. " | |
375 | "Trying out-of-place\n", thisVUC); | |
376 | /* We need to find a targetEUN to fold into. */ | |
377 | targetEUN = NFTL_findfreeblock(nftl, 1); | |
378 | if (targetEUN == BLOCK_NIL) { | |
97894cda | 379 | /* Ouch. Now we're screwed. We need to do a |
1da177e4 LT |
380 | fold-in-place of another chain to make room |
381 | for this one. We need a better way of selecting | |
97894cda | 382 | which chain to fold, because makefreeblock will |
1da177e4 LT |
383 | only ask us to fold the same one again. |
384 | */ | |
385 | printk(KERN_WARNING | |
386 | "NFTL_findfreeblock(desperate) returns 0xffff.\n"); | |
387 | return BLOCK_NIL; | |
388 | } | |
389 | } else { | |
f4a43cfc TG |
390 | /* We put a fold mark in the chain we are folding only if we |
391 | fold in place to help the mount check code. If we do not fold in | |
392 | place, it is possible to find the valid chain by selecting the | |
393 | longer one */ | |
394 | oob.u.c.FoldMark = oob.u.c.FoldMark1 = cpu_to_le16(FOLD_MARK_IN_PROGRESS); | |
395 | oob.u.c.unused = 0xffffffff; | |
8593fbc6 | 396 | nftl_write_oob(mtd, (nftl->EraseSize * targetEUN) + 2 * 512 + 8, |
f4a43cfc TG |
397 | 8, &retlen, (char *)&oob.u); |
398 | } | |
1da177e4 LT |
399 | |
400 | /* OK. We now know the location of every block in the Virtual Unit Chain, | |
401 | and the Erase Unit into which we are supposed to be copying. | |
402 | Go for it. | |
403 | */ | |
404 | DEBUG(MTD_DEBUG_LEVEL1,"Folding chain %d into unit %d\n", thisVUC, targetEUN); | |
405 | for (block = 0; block < nftl->EraseSize / 512 ; block++) { | |
406 | unsigned char movebuf[512]; | |
407 | int ret; | |
408 | ||
409 | /* If it's in the target EUN already, or if it's pending write, do nothing */ | |
410 | if (BlockMap[block] == targetEUN || | |
411 | (pendingblock == (thisVUC * (nftl->EraseSize / 512) + block))) { | |
412 | continue; | |
413 | } | |
414 | ||
f4a43cfc | 415 | /* copy only in non free block (free blocks can only |
1da177e4 | 416 | happen in case of media errors or deleted blocks) */ |
f4a43cfc TG |
417 | if (BlockMap[block] == BLOCK_NIL) |
418 | continue; | |
419 | ||
420 | ret = mtd->read(mtd, (nftl->EraseSize * BlockMap[block]) + (block * 512), | |
421 | 512, &retlen, movebuf); | |
9a1fcdfd | 422 | if (ret < 0 && ret != -EUCLEAN) { |
f4a43cfc TG |
423 | ret = mtd->read(mtd, (nftl->EraseSize * BlockMap[block]) |
424 | + (block * 512), 512, &retlen, | |
425 | movebuf); | |
426 | if (ret != -EIO) | |
427 | printk("Error went away on retry.\n"); | |
428 | } | |
1da177e4 LT |
429 | memset(&oob, 0xff, sizeof(struct nftl_oob)); |
430 | oob.b.Status = oob.b.Status1 = SECTOR_USED; | |
9223a456 | 431 | |
8593fbc6 TG |
432 | nftl_write(nftl->mbd.mtd, (nftl->EraseSize * targetEUN) + |
433 | (block * 512), 512, &retlen, movebuf, (char *)&oob); | |
1da177e4 | 434 | } |
97894cda | 435 | |
f4a43cfc TG |
436 | /* add the header so that it is now a valid chain */ |
437 | oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC); | |
438 | oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum = 0xffff; | |
97894cda | 439 | |
8593fbc6 | 440 | nftl_write_oob(mtd, (nftl->EraseSize * targetEUN) + 8, |
f4a43cfc | 441 | 8, &retlen, (char *)&oob.u); |
1da177e4 LT |
442 | |
443 | /* OK. We've moved the whole lot into the new block. Now we have to free the original blocks. */ | |
444 | ||
97894cda | 445 | /* At this point, we have two different chains for this Virtual Unit, and no way to tell |
1da177e4 LT |
446 | them apart. If we crash now, we get confused. However, both contain the same data, so we |
447 | shouldn't actually lose data in this case. It's just that when we load up on a medium which | |
448 | has duplicate chains, we need to free one of the chains because it's not necessary any more. | |
449 | */ | |
450 | thisEUN = nftl->EUNtable[thisVUC]; | |
451 | DEBUG(MTD_DEBUG_LEVEL1,"Want to erase\n"); | |
452 | ||
97894cda | 453 | /* For each block in the old chain (except the targetEUN of course), |
1da177e4 LT |
454 | free it and make it available for future use */ |
455 | while (thisEUN <= nftl->lastEUN && thisEUN != targetEUN) { | |
456 | unsigned int EUNtmp; | |
457 | ||
f4a43cfc | 458 | EUNtmp = nftl->ReplUnitTable[thisEUN]; |
1da177e4 | 459 | |
f4a43cfc | 460 | if (NFTL_formatblock(nftl, thisEUN) < 0) { |
1da177e4 LT |
461 | /* could not erase : mark block as reserved |
462 | */ | |
463 | nftl->ReplUnitTable[thisEUN] = BLOCK_RESERVED; | |
f4a43cfc | 464 | } else { |
1da177e4 LT |
465 | /* correctly erased : mark it as free */ |
466 | nftl->ReplUnitTable[thisEUN] = BLOCK_FREE; | |
467 | nftl->numfreeEUNs++; | |
f4a43cfc TG |
468 | } |
469 | thisEUN = EUNtmp; | |
1da177e4 | 470 | } |
97894cda | 471 | |
1da177e4 LT |
472 | /* Make this the new start of chain for thisVUC */ |
473 | nftl->ReplUnitTable[targetEUN] = BLOCK_NIL; | |
474 | nftl->EUNtable[thisVUC] = targetEUN; | |
475 | ||
476 | return targetEUN; | |
477 | } | |
478 | ||
479 | static u16 NFTL_makefreeblock( struct NFTLrecord *nftl , unsigned pendingblock) | |
480 | { | |
97894cda | 481 | /* This is the part that needs some cleverness applied. |
1da177e4 LT |
482 | For now, I'm doing the minimum applicable to actually |
483 | get the thing to work. | |
484 | Wear-levelling and other clever stuff needs to be implemented | |
485 | and we also need to do some assessment of the results when | |
486 | the system loses power half-way through the routine. | |
487 | */ | |
488 | u16 LongestChain = 0; | |
489 | u16 ChainLength = 0, thislen; | |
490 | u16 chain, EUN; | |
491 | ||
492 | for (chain = 0; chain < le32_to_cpu(nftl->MediaHdr.FormattedSize) / nftl->EraseSize; chain++) { | |
493 | EUN = nftl->EUNtable[chain]; | |
494 | thislen = 0; | |
495 | ||
496 | while (EUN <= nftl->lastEUN) { | |
497 | thislen++; | |
498 | //printk("VUC %d reaches len %d with EUN %d\n", chain, thislen, EUN); | |
499 | EUN = nftl->ReplUnitTable[EUN] & 0x7fff; | |
500 | if (thislen > 0xff00) { | |
501 | printk("Endless loop in Virtual Chain %d: Unit %x\n", | |
502 | chain, EUN); | |
503 | } | |
504 | if (thislen > 0xff10) { | |
505 | /* Actually, don't return failure. Just ignore this chain and | |
506 | get on with it. */ | |
507 | thislen = 0; | |
508 | break; | |
509 | } | |
510 | } | |
511 | ||
512 | if (thislen > ChainLength) { | |
513 | //printk("New longest chain is %d with length %d\n", chain, thislen); | |
514 | ChainLength = thislen; | |
515 | LongestChain = chain; | |
516 | } | |
517 | } | |
518 | ||
519 | if (ChainLength < 2) { | |
520 | printk(KERN_WARNING "No Virtual Unit Chains available for folding. " | |
521 | "Failing request\n"); | |
522 | return 0xffff; | |
523 | } | |
524 | ||
525 | return NFTL_foldchain (nftl, LongestChain, pendingblock); | |
526 | } | |
527 | ||
97894cda | 528 | /* NFTL_findwriteunit: Return the unit number into which we can write |
1da177e4 LT |
529 | for this block. Make it available if it isn't already |
530 | */ | |
531 | static inline u16 NFTL_findwriteunit(struct NFTLrecord *nftl, unsigned block) | |
532 | { | |
533 | u16 lastEUN; | |
534 | u16 thisVUC = block / (nftl->EraseSize / 512); | |
f4a43cfc | 535 | struct mtd_info *mtd = nftl->mbd.mtd; |
1da177e4 LT |
536 | unsigned int writeEUN; |
537 | unsigned long blockofs = (block * 512) & (nftl->EraseSize -1); | |
538 | size_t retlen; | |
539 | int silly, silly2 = 3; | |
540 | struct nftl_oob oob; | |
541 | ||
542 | do { | |
543 | /* Scan the media to find a unit in the VUC which has | |
544 | a free space for the block in question. | |
545 | */ | |
546 | ||
97894cda | 547 | /* This condition catches the 0x[7f]fff cases, as well as |
1da177e4 LT |
548 | being a sanity check for past-end-of-media access |
549 | */ | |
550 | lastEUN = BLOCK_NIL; | |
551 | writeEUN = nftl->EUNtable[thisVUC]; | |
f4a43cfc | 552 | silly = MAX_LOOPS; |
1da177e4 LT |
553 | while (writeEUN <= nftl->lastEUN) { |
554 | struct nftl_bci bci; | |
555 | size_t retlen; | |
f4a43cfc | 556 | unsigned int status; |
1da177e4 LT |
557 | |
558 | lastEUN = writeEUN; | |
559 | ||
8593fbc6 | 560 | nftl_read_oob(mtd, |
f4a43cfc TG |
561 | (writeEUN * nftl->EraseSize) + blockofs, |
562 | 8, &retlen, (char *)&bci); | |
97894cda | 563 | |
1da177e4 LT |
564 | DEBUG(MTD_DEBUG_LEVEL2, "Status of block %d in EUN %d is %x\n", |
565 | block , writeEUN, le16_to_cpu(bci.Status)); | |
566 | ||
f4a43cfc | 567 | status = bci.Status | bci.Status1; |
1da177e4 LT |
568 | switch(status) { |
569 | case SECTOR_FREE: | |
570 | return writeEUN; | |
571 | ||
572 | case SECTOR_DELETED: | |
573 | case SECTOR_USED: | |
574 | case SECTOR_IGNORE: | |
575 | break; | |
576 | default: | |
577 | // Invalid block. Don't use it any more. Must implement. | |
97894cda | 578 | break; |
1da177e4 | 579 | } |
97894cda TG |
580 | |
581 | if (!silly--) { | |
1da177e4 LT |
582 | printk(KERN_WARNING |
583 | "Infinite loop in Virtual Unit Chain 0x%x\n", | |
584 | thisVUC); | |
585 | return 0xffff; | |
586 | } | |
587 | ||
588 | /* Skip to next block in chain */ | |
589 | writeEUN = nftl->ReplUnitTable[writeEUN]; | |
590 | } | |
591 | ||
97894cda | 592 | /* OK. We didn't find one in the existing chain, or there |
1da177e4 LT |
593 | is no existing chain. */ |
594 | ||
595 | /* Try to find an already-free block */ | |
596 | writeEUN = NFTL_findfreeblock(nftl, 0); | |
597 | ||
598 | if (writeEUN == BLOCK_NIL) { | |
599 | /* That didn't work - there were no free blocks just | |
600 | waiting to be picked up. We're going to have to fold | |
601 | a chain to make room. | |
602 | */ | |
603 | ||
604 | /* First remember the start of this chain */ | |
605 | //u16 startEUN = nftl->EUNtable[thisVUC]; | |
97894cda | 606 | |
1da177e4 LT |
607 | //printk("Write to VirtualUnitChain %d, calling makefreeblock()\n", thisVUC); |
608 | writeEUN = NFTL_makefreeblock(nftl, 0xffff); | |
609 | ||
610 | if (writeEUN == BLOCK_NIL) { | |
97894cda | 611 | /* OK, we accept that the above comment is |
1da177e4 LT |
612 | lying - there may have been free blocks |
613 | last time we called NFTL_findfreeblock(), | |
614 | but they are reserved for when we're | |
615 | desperate. Well, now we're desperate. | |
616 | */ | |
617 | DEBUG(MTD_DEBUG_LEVEL1, "Using desperate==1 to find free EUN to accommodate write to VUC %d\n", thisVUC); | |
618 | writeEUN = NFTL_findfreeblock(nftl, 1); | |
619 | } | |
620 | if (writeEUN == BLOCK_NIL) { | |
621 | /* Ouch. This should never happen - we should | |
97894cda TG |
622 | always be able to make some room somehow. |
623 | If we get here, we've allocated more storage | |
1da177e4 LT |
624 | space than actual media, or our makefreeblock |
625 | routine is missing something. | |
626 | */ | |
627 | printk(KERN_WARNING "Cannot make free space.\n"); | |
628 | return BLOCK_NIL; | |
97894cda | 629 | } |
1da177e4 LT |
630 | //printk("Restarting scan\n"); |
631 | lastEUN = BLOCK_NIL; | |
632 | continue; | |
633 | } | |
634 | ||
635 | /* We've found a free block. Insert it into the chain. */ | |
97894cda | 636 | |
1da177e4 | 637 | if (lastEUN != BLOCK_NIL) { |
f4a43cfc | 638 | thisVUC |= 0x8000; /* It's a replacement block */ |
1da177e4 | 639 | } else { |
f4a43cfc TG |
640 | /* The first block in a new chain */ |
641 | nftl->EUNtable[thisVUC] = writeEUN; | |
1da177e4 LT |
642 | } |
643 | ||
644 | /* set up the actual EUN we're writing into */ | |
645 | /* Both in our cache... */ | |
646 | nftl->ReplUnitTable[writeEUN] = BLOCK_NIL; | |
647 | ||
648 | /* ... and on the flash itself */ | |
8593fbc6 | 649 | nftl_read_oob(mtd, writeEUN * nftl->EraseSize + 8, 8, |
f4a43cfc | 650 | &retlen, (char *)&oob.u); |
1da177e4 LT |
651 | |
652 | oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC); | |
653 | ||
8593fbc6 | 654 | nftl_write_oob(mtd, writeEUN * nftl->EraseSize + 8, 8, |
f4a43cfc | 655 | &retlen, (char *)&oob.u); |
1da177e4 | 656 | |
f4a43cfc | 657 | /* we link the new block to the chain only after the |
1da177e4 LT |
658 | block is ready. It avoids the case where the chain |
659 | could point to a free block */ | |
f4a43cfc | 660 | if (lastEUN != BLOCK_NIL) { |
1da177e4 LT |
661 | /* Both in our cache... */ |
662 | nftl->ReplUnitTable[lastEUN] = writeEUN; | |
663 | /* ... and on the flash itself */ | |
8593fbc6 | 664 | nftl_read_oob(mtd, (lastEUN * nftl->EraseSize) + 8, |
f4a43cfc | 665 | 8, &retlen, (char *)&oob.u); |
1da177e4 LT |
666 | |
667 | oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum | |
668 | = cpu_to_le16(writeEUN); | |
669 | ||
8593fbc6 | 670 | nftl_write_oob(mtd, (lastEUN * nftl->EraseSize) + 8, |
f4a43cfc | 671 | 8, &retlen, (char *)&oob.u); |
1da177e4 LT |
672 | } |
673 | ||
674 | return writeEUN; | |
675 | ||
676 | } while (silly2--); | |
677 | ||
678 | printk(KERN_WARNING "Error folding to make room for Virtual Unit Chain 0x%x\n", | |
679 | thisVUC); | |
680 | return 0xffff; | |
681 | } | |
682 | ||
683 | static int nftl_writeblock(struct mtd_blktrans_dev *mbd, unsigned long block, | |
684 | char *buffer) | |
685 | { | |
686 | struct NFTLrecord *nftl = (void *)mbd; | |
687 | u16 writeEUN; | |
688 | unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1); | |
689 | size_t retlen; | |
690 | struct nftl_oob oob; | |
691 | ||
692 | writeEUN = NFTL_findwriteunit(nftl, block); | |
693 | ||
694 | if (writeEUN == BLOCK_NIL) { | |
695 | printk(KERN_WARNING | |
696 | "NFTL_writeblock(): Cannot find block to write to\n"); | |
697 | /* If we _still_ haven't got a block to use, we're screwed */ | |
698 | return 1; | |
699 | } | |
700 | ||
701 | memset(&oob, 0xff, sizeof(struct nftl_oob)); | |
702 | oob.b.Status = oob.b.Status1 = SECTOR_USED; | |
1da177e4 | 703 | |
8593fbc6 TG |
704 | nftl_write(nftl->mbd.mtd, (writeEUN * nftl->EraseSize) + blockofs, |
705 | 512, &retlen, (char *)buffer, (char *)&oob); | |
1da177e4 LT |
706 | return 0; |
707 | } | |
708 | #endif /* CONFIG_NFTL_RW */ | |
709 | ||
710 | static int nftl_readblock(struct mtd_blktrans_dev *mbd, unsigned long block, | |
711 | char *buffer) | |
712 | { | |
713 | struct NFTLrecord *nftl = (void *)mbd; | |
f4a43cfc | 714 | struct mtd_info *mtd = nftl->mbd.mtd; |
1da177e4 LT |
715 | u16 lastgoodEUN; |
716 | u16 thisEUN = nftl->EUNtable[block / (nftl->EraseSize / 512)]; | |
717 | unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1); | |
f4a43cfc | 718 | unsigned int status; |
1da177e4 | 719 | int silly = MAX_LOOPS; |
f4a43cfc TG |
720 | size_t retlen; |
721 | struct nftl_bci bci; | |
1da177e4 LT |
722 | |
723 | lastgoodEUN = BLOCK_NIL; | |
724 | ||
f4a43cfc | 725 | if (thisEUN != BLOCK_NIL) { |
1da177e4 | 726 | while (thisEUN < nftl->nb_blocks) { |
8593fbc6 | 727 | if (nftl_read_oob(mtd, (thisEUN * nftl->EraseSize) + |
f4a43cfc TG |
728 | blockofs, 8, &retlen, |
729 | (char *)&bci) < 0) | |
1da177e4 LT |
730 | status = SECTOR_IGNORE; |
731 | else | |
732 | status = bci.Status | bci.Status1; | |
733 | ||
734 | switch (status) { | |
735 | case SECTOR_FREE: | |
736 | /* no modification of a sector should follow a free sector */ | |
737 | goto the_end; | |
738 | case SECTOR_DELETED: | |
739 | lastgoodEUN = BLOCK_NIL; | |
740 | break; | |
741 | case SECTOR_USED: | |
742 | lastgoodEUN = thisEUN; | |
743 | break; | |
744 | case SECTOR_IGNORE: | |
745 | break; | |
746 | default: | |
747 | printk("Unknown status for block %ld in EUN %d: %x\n", | |
748 | block, thisEUN, status); | |
749 | break; | |
750 | } | |
751 | ||
752 | if (!silly--) { | |
753 | printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%lx\n", | |
754 | block / (nftl->EraseSize / 512)); | |
755 | return 1; | |
756 | } | |
757 | thisEUN = nftl->ReplUnitTable[thisEUN]; | |
758 | } | |
f4a43cfc | 759 | } |
1da177e4 LT |
760 | |
761 | the_end: | |
762 | if (lastgoodEUN == BLOCK_NIL) { | |
763 | /* the requested block is not on the media, return all 0x00 */ | |
764 | memset(buffer, 0, 512); | |
765 | } else { | |
766 | loff_t ptr = (lastgoodEUN * nftl->EraseSize) + blockofs; | |
767 | size_t retlen; | |
9a1fcdfd TG |
768 | int res = mtd->read(mtd, ptr, 512, &retlen, buffer); |
769 | ||
770 | if (res < 0 && res != -EUCLEAN) | |
1da177e4 LT |
771 | return -EIO; |
772 | } | |
773 | return 0; | |
774 | } | |
775 | ||
776 | static int nftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo) | |
777 | { | |
778 | struct NFTLrecord *nftl = (void *)dev; | |
779 | ||
780 | geo->heads = nftl->heads; | |
781 | geo->sectors = nftl->sectors; | |
782 | geo->cylinders = nftl->cylinders; | |
783 | ||
784 | return 0; | |
785 | } | |
786 | ||
787 | /**************************************************************************** | |
788 | * | |
789 | * Module stuff | |
790 | * | |
791 | ****************************************************************************/ | |
792 | ||
793 | ||
794 | static struct mtd_blktrans_ops nftl_tr = { | |
795 | .name = "nftl", | |
796 | .major = NFTL_MAJOR, | |
797 | .part_bits = NFTL_PARTN_BITS, | |
19187672 | 798 | .blksize = 512, |
1da177e4 LT |
799 | .getgeo = nftl_getgeo, |
800 | .readsect = nftl_readblock, | |
801 | #ifdef CONFIG_NFTL_RW | |
802 | .writesect = nftl_writeblock, | |
803 | #endif | |
804 | .add_mtd = nftl_add_mtd, | |
805 | .remove_dev = nftl_remove_dev, | |
806 | .owner = THIS_MODULE, | |
807 | }; | |
808 | ||
809 | extern char nftlmountrev[]; | |
810 | ||
811 | static int __init init_nftl(void) | |
812 | { | |
97894cda | 813 | printk(KERN_INFO "NFTL driver: nftlcore.c $Revision: 1.98 $, nftlmount.c %s\n", nftlmountrev); |
1da177e4 LT |
814 | |
815 | return register_mtd_blktrans(&nftl_tr); | |
816 | } | |
817 | ||
818 | static void __exit cleanup_nftl(void) | |
819 | { | |
820 | deregister_mtd_blktrans(&nftl_tr); | |
821 | } | |
822 | ||
823 | module_init(init_nftl); | |
824 | module_exit(cleanup_nftl); | |
825 | ||
826 | MODULE_LICENSE("GPL"); | |
827 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>, Fabrice Bellard <fabrice.bellard@netgem.com> et al."); | |
828 | MODULE_DESCRIPTION("Support code for NAND Flash Translation Layer, used on M-Systems DiskOnChip 2000 and Millennium"); |